Pension and Other Postretirement Benefits (Tables)

9 Months Ended

Sep. 30, 2017

Retirement Benefits [Abstract]

Components of Net Periodic Benefit Cost

The components of net periodic benefit cost were as follows:

	Third quarter ended September 30,						Nine months ended September 30,
	2017			2016**			2017			2016**
Pension benefits
Service cost	$	18		$	18		$	53		$	42
Interest cost		62			44			183			81
Expected return on plan assets		(101	)		(80	)		(298	)		(140	)
Recognized net actuarial loss		47			36			139			55
Amortization of prior service cost		2			2			6			5
Settlements*		3			13			3			13
Special termination benefits*		–			–			3			1
Net periodic benefit cost	$	31		$	33		$	89		$	57

* These amounts were recorded in Restructuring and other charges on the accompanying Statement of Consolidated Operations (see Note D).

** In the 2016 third quarter and nine-month period, Alcoa Corporation also recognized multiemployer expense related to pension benefits of $8 and $53, respectively.

	Third quarter ended September 30,						Nine months ended September 30,
	2017			2016*			2017			2016*
Other postretirement benefits
Service cost	$	2		$	1		$	4		$	1
Interest cost		9			6			28			8
Recognized net actuarial loss		3			3			10			3
Amortization of prior service benefit		(1	)		(2	)		(4	)		(2	)
Net periodic benefit cost	$	13		$	8		$	38		$	10

* In the 2016 third quarter and nine-month period, Alcoa Corporation also recognized multiemployer expense related to other postretirement benefits of $2 and $19, respectively.